1. Field of the Invention
This invention relates to illumination of a visual display terminal and more particularly to the illumination of the keyboard.
2. Description of the Prior Art
With advances in technology, most every office, including small business firms and even private homes, are equipped with visual display terminals including a screen and keyboard. The proper balance of room lighting, along with the absence of glare for screen readability, and adequate keyboard illumination has not been achieved through previous patents.
For example, U.S. Pat. No. 4,173,034 to Schemitz discloses a fixture with a reflector which reflects a portion of the incident light toward the ceiling and transmits a portion of the light to the area below the fixture. In Shemitz, the light is directed at the screen as well as the keyboard.
U.S. Pat. No. 4,414,609, again to Shemitz, discloses a system providing a back lighting component as well as task and ambient lighting. A visual display terminal luminaire is provided which directs a portion of the light output of the luminaire to the wall or back panel behind the display terminal. By directing the light to the back wall, Schemitz decreases the lighting contrast on the screen, thus decreasing the readability of the screen. The Shemitz patent does not decidedly increase the visability of the keyboard.
No prior art device is known in connection with visual display terminals that improves the readability of the screen at the same time it improves the illumination of the keyboard and the work surface.